They are radically different designs. The AQ Diamond has silver conductors, the Decade has copper conductors. They are both very good cables in their class. That meaning the AQ Diamond, being silver, is quicker, cleaner and more transparent, while the TL Decade is smoother, warmer and fuller. The Decade is quick and clear, for a copper cable and the Diamond is smoother then some silver cables I've heard. That being said, only you know your musical tastes, and will have to ultimately decide whether you prefer the speed of the silver over the warmth of copper. Personally, I find that the ancillary equipment has a lot to do with how I feel about these cables. I prefer the AQ with tube equipment and the TL with solid state equipment.

It's always interesting how each of us has such different experiences, priorities, likes, etc. About 7 years ago I was on a quest to find a great interconnect between my pre (ARC LS5) and amp (ARC CL60). After so much praise on the AQ Diamond, I borrowed one for a trial period. I also borrowed NBS Master and Transparent Ultra from an other dealer. At this time, I owned Straightwire Virtuoso and SilverAudio SilverBullet 6. So I had a lot of opportunity to listen to many cables.

The AQ was one of the biggest disappointments. I honestly do not know how these could be described as having 3D qualities at all. I worked hard to achieve a system of harmonic richness, bloom, great decays, etc., with the LS5, and the AQ literally destroyed these qualities in an instant. Perhaps for a system where such strengths are not there, the AQ might be fine. It did have a very neutral tonal balance so it was not fatiguing like the Straightwire, nor rolled off on the high freqs like the Transparent Ultra. But musical, the AQ was not. And a cable is not supposed to be musical. But if it removes the emotional content of the music, then something is fundamentally wrong. None of the other cables tested here had this attribute.

The NBS Master was a most incredible cable with resolution and the 3-dimensionality like I had not heard from any other cable. And I never heard of NBS until the dealer suggested I try it.

This whole experience also indicated to me that link where the biggest differences could be heard was from pre to amp.There's so much coverage here about cables as tone controls. A whole lot of a cable's quality has more to do with its resolution. The NBS was as neutral as the AQ but brought the out real performance.

You don't mention your system or the current cables you are using and improvements you are hoping to achieve.

Jafox even cable need matching on our gear,I am gladyou cleared it,maybe the AQ did not match your system,The AQ did have 3D,but when we put it on onothersystem it did not have it, so its the system thatis not capable.

oooops NO mention of the version there. X, X2, X3...weird.Testing its younger siblings in the AQ copper line....Audioquest Emerald X versus X3......THEY do not sound the same..SO i reckon a testing for the Audioquest Diamond X is not representative of the X3.

OLD AQ emerald- had a warmer presentation and the nuances were more masked than the new one X3